From an IGN interview:
Chip Architect Speaks About Xbox 360 and PS3 Creation
But which is more powerful in the end?
January 16, 2009 - Gamasutra.com secured an interview with David Shippy who was the chief architect of the power processing unit for the Cell (the engine that drives the PS3). The chip began the research and design process in 2000 when Sony asked IBM for an "order of magnitude increase in processing performance." Ironically it was that very ambition and the design that followed that would one day be the foundation for Microsoft's Xbox 360.
Shippy describes the design goals as shooting for a "supercomputer on a chip" and says "We came along with Cell and we were double the frequency of any PC out there." Then in 2003 Microsoft comes to IBM and, much like Sony, asked them to design a chip unlike anything that was currently on the market. Naturally, IBM showed The Big M their latest and greatest tech which, at that time, was the multi-core "road map" that was used to create what would eventually become the Cell. Keep in mind, that all of this original technology was originally financed by Sony and Toshiba for use in the PS3.
Shippy maintains that Microsoft never got a look at the actual Cell processor and maintains that it was IBM's right to sell the technology to other platforms, such as the Xbox 360, but also states, "The Cell itself and the fundamental architecture that went into that -- that was all proprietary for PS3."
Even still, the fact remains that Xbox 360 chip designers and PS3 chip designers were, at one time, working side-by-side with one another at IBM. Shippy details distaste that developed between the two teams, "when this whole Xbox thing came in, there were certainly a lot of guys -- even on my team -- that were fairly upset about it."
But when asked the flame war inducing question, "which console is actually more powerful?"
Shippy tells Gamasutra, "I'm going to have to answer with an 'it depends.' Again, they're completely different models. So in the PS3, you've got this Cell chip which has massive parallel processing power, the PowerPC core, multiple SPU cores… it's got a GPU that is, in the model here, processing more in the Cell chip and less in the GPU. So that's one processing paradigm -- a heterogeneous paradigm."
"With the Xbox 360, you've got more of a traditional multi-core system, and you've got three PowerPC cores, each of them having dual threads -- so you've got six threads running there, at least in the CPU. Six threads in Xbox 360, and eight or nine threads in the PS3 -- but then you've got to factor in the GPU," Shippy explains. "The GPU is highly sophisticated in the Xbox 360."
"At the end of the day, when you put them all together, depending on the software, I think they're pretty equal."
Shippy then goes on to dissect each console's flaws: for the Xbox 360 it was the initial heatsink and cooling problems and for the PS3 it's the coding issues experienced by developers. While Shippy was not directly involved in the programming of the Xbox 360's power consumption, his best guess is that Microsoft brought their system specs right up to the edge of functioning properly and melting down which Shippy describes as "playing with fire."
On the PS3's supposed programming issues Shippy says it's "definitely a new paradigm" but claims that once developers wrap their head around the nuances of the system, they can actually get impressive results for "low-level coding."
